April Daisy Lab
KOEN
WATER FOR COFFEE

Water Guide_

Explore the inside of filters, and the water you brew with.

What it removes.
What it is made of.
How it changes the water.

6 TYPES / 2 VIEWS

01 / Filter Atlas

Water directionExterior + exploded section
06 / 06
01SEDIMENT

Sediment filter

Fibrous layers capture suspended particles.

Media
Polypropylene (PP) fibers
Effect
Captures sand, rust and sediment

↳Does not adjust dissolved minerals or hardness.

PRODUCT EXAMPLEPentair Pentek P5 / P Series
Principle · product notes · sources

A typical depth filter captures particles as water moves from outside to inside. Fiber density and filter rating affect retention and pressure loss.

Depth filtration with PP fibers of increasing density from outside to inside.

An example of PP depth media. Compare WP for string-wound media and R Series for pleated media.

02CARBON BLOCK

Carbon block filter

Water passes through a bonded block of activated carbon.

Media
Bonded powdered activated carbon (PAC)
Effect
Reduces chlorine and unwanted odors

↳Carbon filtration alone does not lower hardness.

PRODUCT EXAMPLEPentair Pentek CBC-10
Principle · product notes · sources

Water moves through a porous block into the central channel. It is used for chlorine reduction and organic adsorption; particle retention depends on the product rating.

CBC uses bonded powdered activated carbon. Carbon feedstock and filter ratings vary by product.

03GRANULAR CARBON

Granular carbon filter

Water travels through a bed of activated carbon granules.

Media
Granular activated carbon (GAC)
Effect
Reduces chlorine and unwanted odors

↳Contact time and channeling affect treatment.

PRODUCT EXAMPLEPentair Pentek GAC-10
Principle · product notes · sources

Products such as Pentek GAC direct water from one end through the full carbon bed to the other. A downstream filter retains carbon fines.

Granular carbon with a PP post-filter, designed to route water through the carbon bed.

04Na⁺ ION EXCHANGE

Sodium-form softener

Exchanges calcium and magnesium for sodium ions.

Media
Na⁺-form strong-acid cation resin
Effect
Lowers total hardness · increases Na⁺

↳Conventional Na-form softening does not lower alkalinity.

PRODUCT EXAMPLEBRITA PURITY C Finest C150
Principle · product notes · sources

A typical resin uses spherical styrene–DVB beads with sulfonic groups. Regenerable systems restore exchange capacity using NaCl brine. Replaceable cartridges use a different maintenance approach.

Officially documented: total-hardness reduction plus carbon and other filtration stages, at 0% bypass. The drawing shows a generic Na-form principle, not the product’s internal formulation or cross-section.

05H⁺ DECARBONISATION

Hydrogen-form decarboniser

H⁺-form resin reduces carbonate hardness and alkalinity.

Media
H⁺-form weak-acid cation resin
Effect
Lowers carbonate hardness and alkalinity

↳A different principle from hydrogen-water generation.

PRODUCT EXAMPLEBRITA PURITY C Quell ST
Principle · product notes · sources

A typical material is acrylic resin with carboxylic groups. Released H⁺ reacts with bicarbonate. Check treated-water pH, CO₂ and blending ratio.

Officially documented: decarbonisation and carbonate-hardness reduction. Head bypass settings depend on source water and application. The drawing illustrates a generic H-form principle, without specifying the product’s internal formulation.

06REVERSE OSMOSIS

Reverse osmosis filter

Pressure drives water through a membrane to reduce dissolved substances.

Media
Polyamide thin-film composite (TFC) membrane
Effect
Reduces dissolved salts and minerals

↳Blending or remineralisation is a separate step for coffee.

PRODUCT EXAMPLEDuPont FilmTec TW30-1812-50HR
Principle · product notes · sources

A membrane with polyamide, polysulfone and polyester support layers is spiral-wound. Feed water separates into permeate and concentrate. Pretreatment and operating pressure affect performance.

An example of a spiral-wound polyamide TFC element. This is a membrane component, not a complete coffee-water system.

The drawings compare media and principles. Product names are real examples, not internal engineering drawings or a performance ranking.

02 / Water Adjustment

PRINCIPLE → OPERATION
Na

Soften with resin, regenerate with brine

Hard water→Na⁺ resin→Softened
NaCl⇢Resin regeneration⇢Drain

NaCl and ion-exchange resin are not separate softening principles. Regenerable systems reuse the resin with brine; replaceable cartridges are changed when exhausted.

Purolite · Softening & regeneration ↗
Mix

Blending and remineralisation differ

Treated+Bypass→Blend
RO+Minerals→Remineralised

Blending recombines water routed outside a treatment path. Remineralisation adds minerals. Check the product’s allowed settings and resulting water composition.

Finest specifies 0% bypass. One blending setting does not apply to every filter.

03 / Before Choosing

01Know your source waterCheck total hardness, alkalinity and chlorine separately.

02Look beyond TDSThe same TDS can represent different mineral compositions.

03Check after treatmentFlow, service life and blending settings affect treated water.

Research scope and references⌄

This guide summarises public manufacturer documentation. Resin materials refer to representative Purolite media, not BRITA’s undisclosed formulations.

BRITA · How filtration affects coffee flavour ↗CDC · Home water treatment ↗

01 Feed · 02 Treated water · 03 Media · 04 RO layers

RO: 02a Permeate · 02b Concentrate. A conceptual drawing, not a product cross-section.